There has been available various sealed cartons or packages which, under normal circumstances, must be torn open or in some respect destroyed in order to permit access to the contents. These cartons have typically employed overlapping panels or flaps which are adhesively bonded to carton walls so that opening of the carton effectively destroys the carton and provides visual indication that someone has gained access to the carton interior.
To improve upon these cartons, some carton designs have employed sealed flaps having cuts or perforations therein which define a score line, whereby any attempt to gain access by breakage of the seal causes distortion or tearing of the flap. These arrangement again provide visual evidence of any alleged tampering with the carton. Structures of this type are illustrated by U.S. Pat. Nos. 4,508,226, 4,479,588, 4,434,896 and 4,573,634.
While cartons of the aforementioned type are satisfactory, nevertheless they are limited as to their field of application. That is, these known cartons are typically constructed of paperboard, the latter basically comprising a single ply or layer, with the cartons being of small size so as to typically contain therein a single object, such as a tube of toothpaste. Further, the tamper-resistant sealed closure associated with these paperboard cartons has been designed so as to be primarily suitable solely with paperboard, and as such the known tamper-resistant arrangements have not been suitable for use with heavier cartons, such as larger shipping cartons of the type constructed from corrugated cardboard.
At the present time, large and heavy-duty boxes constructed of corrugated cardboard are used for shipping many products, such as the bulk shipment of food products and the like. Such corrugated cardboard cartons, however, have not been provided with any satisfactory means of providing an effective tamper-resistant seal structure.
Accordingly, it is an object of the present invention to provide an improved carton constructed of corrugated cardboard and provided with a tamper-resistant closure or sealing structure associated therewith.
More specifically, it is an object of this invention to provide an improved corrugated cardboard carton, as aforesaid, wherein the carton has opposed foldable outer flaps associated with the top and bottom ends of the carton, which opposed outer flaps overlap inner flaps in a conventional manner, with the opposed outer flaps being sealed together adjacent their free edges. To create a tamper-resistant seal structure between the outer flaps, the flaps terminate in free edges which effectively abut when the carton is closed, which free edges are defined solely by the inner facing layer and the intermediate corrugated layer of the board stock defining the flaps. The outer facing layer of the board stock defining the flaps, however, is provided with a securing strip which is integral therewith and which projects outwardly beyond the free edge. This securing strip is provided with cuts or openings therethrough. The outer facing layer of the flap also has an indicator strip, preferably of a bright color, formed on the exterior face thereof and extending longitudinally along the flap adjacent to but spaced slightly inwardly from the free edge. When the opposed outer flaps are closed so that the free edges are disposed closely adjacent but in nonoverlapping relationship, the securing strip on one flap overlaps the outer facing layer of the other flap and is adhesively sealed thereto. The cuts or openings associated with the one flap are disposed directly over the indicator strip on the other flap. Hence, any unauthorized attempt to unseal the strip and then reseal the carton results in the cuts or openings being distorted, and such distortion is particularly evident due to the bright color of the underlying indicating strip. Unauthorized opening or tampering of the shipping carton can thus be readily observed.
Other objects and purposes of the invention will be apparent to persons familiar with structures of this general type upon reading the following specification and inspecting the accompanying drawings.